Boiler construction



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R C CROSS BOILER- CONSTRUCTION Filed April 7,'1944 S MN 0d 89 194s. R.c. cmss y 2,408,968

A BOILER CONSTRUCTION Fiied April 7. 1.944 5 sheets-sheet s Patented ct.8, 1946 BOILER CONSTRUCTION Robert C. Cross, Riverside, Ill., assignorto Sears, Roebuck and Co., Chicago, Ill., a corporation of New YorkApplication April 7, 1944, Serial No. 529,986l

2 Claims.

The present invention relates to improvements in the construction anddesign of radiation heating boilers for use in either steam or hot watersystems to be red by means of oil or gas burning devices.

A principal object is to achieve a more compact design to be operatedfor producing more eniciently the circulation of the heating medium,while attaining esthetic results in the over-all outline of the boilerassembly under various arrangements of boiler 'sectional composition.

In the construction of heating boilers for use in steam o-r hot watersystems, it has been known to provide intermediate sectional units whichmay be varied in quantity so as to accordingly regulate the capacity ofthe boiler according to specific requirements.

In the herewith proposed apparatus it is a further object to utilize acast iron sectional boiler construction for oil or gas burning heatersystems in which the variable sections are provided with staggeredlwater tubes so as to break up the combustion flue stream with inclinedsection elements that effect an eilicient heat exchange medium whileinducing a free natural water flow from the rear to the fore portions ofthe assembly.

In order to achieve the objects declared above, there is herewithproposed a boiler design incorporating the features of interchangeablemultiple section assembly in which each section is constituted of upperand lower header portions connected by staggered and inclined watertubes of tear-drop cross-section so as to insure the rapid and eiiicientflow of Water in'the boiler, and to utilize to a maximum degree thenatural ilow of heated flue gases in order to effect a thorough heatexchange by conduction, to expose a minimum top surface to theaccumulation of soot deposit which tends to create a heat deterrent andinsulation, and to achieve these and other eniciency motives whilemaintaining an over-all graceful and pleasing contour that lends itselfto facile jacketing and artistic enclosure.

For a better understanding of how the foregoing objects are attained andthe details concerning the constructional features of this apparatus,reference will now be had to the accompanying drawings and to thefollowing detailed speciiication in which like reference charactersdesignate corresponding parts throughout and in which:

Fig. l is a front elevation of a boiler embodying the characteristics ofthis invention with an illustrative jacketing structure in section;

Fig. 2 is a plan sectional View of the boiler illustrated in Fig. l.,taken approximately on line 2--2 thereof;

Fig. 3 is a vertical sectional view of the apparatus featured in Figs. 1and 2, taken approximately on the line 3-3 of Fig. 2;

Fig. 4 is a fragmentary vertical sectional view enlarged taken at onecorner of the sectionalized boiler construction as indicated on line 4-4of Fig. 2;

Fig. 5 is a vertical sectional View of the boiler construction featuredin the foregoing figures and taken on a line indicated 5-5 on Figs. land 2, indicating an oil burner device and exhaust .pipe attached;

Fig. 6 is a Vertical elevational view of a modied boiler constructionembodying the features of the present invention for use with a gasburning heat element;

Fig. '7 is a detailed perspective View of a flanged control receptacletting adapted for use with a heating boiler embodying 'the features ofthe present invention.

Fig. 8 is a detailed perspective View of an exemplary boilei` sectionalunit with portions of .the inclined connecting flues broken away toindicate their conformation; and

Fig. 9 is a plan View of the boiler section featured in Fig. 8, havingportions broken away to reveal the construction of the lleted fluejunctures.

Referring now more particularly to the accom-- panying drawings, thereference character l designates a combustion chamber or base castingdesigned for use in conjunction with an oil burning chamber. This memberis ywater jacketed as at 2 on its vertical sides and on the bottom, alining of fire clay or other refractory material shaped to produce thedesired flame convection, being provided to line the inner chamber ofthe base I and thereby constituting the combustion chamber which isdisposed centrally and beneath the water tubes 6 which will be discussedin greater extent later. The upper edges of the surrounding Verticalwall sections of the base casting including a transverse jacketed frontwall 2a are inclined with the fore portion at a higher ele- Vation, asbest indicated in Fig. 5, than that of the rear portion, conforming inthis respect to the angle of inclination oi the several intermediatesections 4 and 5 with respect to their forward and rearward headerportions 1 and 8. The 'number of sections 4 and 5 which may be providedinthe assembling of each unit heating boiler will vary in accordancewith; the heating capacity required by the specific installationproblems. Alternate sections are preferably of identical design, whilecontiguous ones preferably differ from each other in respect to thenurnber and relative disposition of their water tubes E, as bestindicated in Fig. 3. Specifically this arrangement provides for thedisplacement of the consecutive tubes at intervening points in verticalalinement `so that the heated gases rise and pass through the boilersections where current deflections and eddy streams formed upon engagingthe rounded lower surfaces of the several tubes 6 are broken up by thestaggered arrangement of consecutive sections causing 'the air streamsto be driven into closer contactual engagement and eiecting thereby amore complete transfer of heat from these gases to the tubular elements6.

The sections 4 and 5 are otherwise of identical formation and each isprovided with four corner push nipple openings that flare with a gradualtaper in accordance with conventional boiler assembly practice, so thateach with its adjacent section may be integrated to form a continuouspassageway with the other internally by connection of push nipples 9that are received in the nipple boss formations III. The lowermostsection 5 is connected in a similar manner with the base casting I,while the uppermost section 4 is thus connected to an upper dome castingI2. In this way the entire water space of the dome, base, andintermediate sections is rendered continuous and the assembly, afterbeing cemented for sealing, is clamped together by means of externaldraw bolts I8 which pass through dome section ears ISa and base sectionears ISD, as clearly illustrated in Figs. 1 and 6.

As a result of the inclination in the water tubes 6 of the intermediateboiler sections, the water content is facilitated in rising in adirection from the rearmost part of the boiler unit to the foremostpart, thereby constituting the primary factor in promoting a maximumeiiiciency circulation of this fluid internally of the boiler unit whichmakes for the proper mixing of cooler incoming or return fluid with thecontentsof the unit and the introduction of maximum heated fluid at thefore portion of the dry pipe 24 when used as a water boiler. The drypipe 24 is provided with upper surface perforations 25 after the mannerof conventional boiler design practice, thus effectively providing ameans of insuring the delivery of dry steam to a steam heating system;The pipe 24 also serves the purpose of insuring proper internal boilercirculation when used as a hot water boiler.

In addition to the aforedescribed control of internal water or steamcirculation, a further design feature is provided which will beexplained with particular reference to Fig. 9. There it will be notedthat the water tubes 6 join their respective headers 1 and 8 forming atthe point of juncture arcuate fillets having on the one hand majorradius junctures as at 33 and opposite thereto minor radius junctures asat 34; As the flow of water from the lower to the higher header levelsapproaches the juncture, the tendency upon encountering major radiusturns is to induce water circulation in that direction as against sharpturning in the direction of the minor radius 34. All of the tubes 6 arethus designed, save the central tube, in the case of a section having anodd number of flue pipes. The major radius fillets 33 cause the waterflow from the pipes to be directed in a preferential current toward theouter extremity with reference to a median line paralleling the centerilue pipe. The general effect therefore is to induce clockwise andcounter-clockwise current flow in each section in terms 5 of each halfthereof with the aforedescribed median line as an intermediate boundary.This circulation control assures a lateral rotary movement incombination with the forward movement which is induced by theinclination of the water tubes 6.

The base casting I is provided with two water return embossments I4toeither or both of which there may be connected the cold water returnpipes from the circulating system depending upon the conveniences of agiven installation. The water enteringr therethrough, being relativelycolder, will become heated by conduction due to its exposure to theWalls of the fire box and as it is heated will rise within the boilertraveling through a course as above outlined, including the angularlydisposed tubes 6 to the right or to the left of the vertical center ofthe boiler to be drawn into the system for circulation again through theheader circulating pipe 25. In the case of a steam system, the heatingof the return vapor will travel through a similar course as is wellknown in circulating heating systems.

Referring now again to the arrangement and disposition of theinterchangeable boiler sections 5, attention is directed to therelatively narrow construction of the front or upper headers 1, as bestindicated in Fig, 5, and by contrast therewith the flared and relativelywider construction of the rear or lower headers 8 which are providedwith abutting rib formations 8a so as to form a continuous closedsurface to that region of the boiler in contrast with the accessibleopenings Ia which intervene sections 1.

Clean-out door 35 indicated in both embodiments, Figs. 5 and 6, isparticularly essential in the oil burning system to provideaccessibility for removing soot deposits from the upper surfaces of thewater tubes that may be reached by con ventional cleaning brushes byprojecting them through the aforedescribed spaces 1a that intervenesections l'. In this way a maximum heating efliciency of the boilersections may be maintained at all times, although the tear-dropcross-scctional design of the flues E affords a further advantage ofminimizing heat exchange losses due to soot deposit insulation by reasonof the fact that minimum surface areas are afforded to give support tosuch deposits.

Narrow spacing slots I6, Fig. 6, between the adjacent outer waterwaysI5, see also Fig. 3, may

be lled in with furnace cement or other ealking material whereby thereis sealed the heating space which extends from the combustion chamber tothe flue pipe 20 iitted on the flue pipe collar 2l.

No leakage losses result from the openings which face the clean-out door35 during the time that this door is closed, and accordingly there isobtained an efficient leak-proof heat chamber that is neverthelessaccessible for periodic cleaning purposes. At the inner end of thepassageway,

which is co-extensive with cellar 2|, there are formed radial fins 22which serve as a final means to absorb the heat from the outgoing gases,transferring it to the adjacent water space in the boiler 0 section I2.Similar rib formations may also be provided in the bottom surface Ia ofthe boiler section I2, which defines the ceiling of the combustionchamber and which lies just beneath the dry Pipe 24.

The dry pipe is preferably carried by a special pipe fitting 36, Fig. 7,which is secured to the boiler head by its bolted flange 3l and which isprovided with a pair of horn formations 38 threaded to receive specialimmersion type fittings or si'rdevices, for example, pressure control atus, safety valves or temperature regulators. The steam or water mainsupply line 2t is screw threaded into the body of the tting 35 in axialalinement with the dry pipe 24 and openings for similar headerconnections may be provided in one or two places as in the case of thereturn pipe embossments lil, depending upon specific requirements.

Fig. 5 indicates the location of an oil burner nozzle 2 with relation tothe re box space and shows the manner in which this apparatus isprojected through a front panel 28 of the base section i with the rearwall of the retort box appropriately curved to impart a rotary now ofthe heating flame from the nozzle 21 according to the curvaturedesignated 29 in the lining material. An observation port having aprotective glass window 3i? may be provided in the panel 23 throughwhich may be seen the performance of the oil burner and draft movementimparted to its flame. An immersion type water heating unit 32 may alsobe provided to serve as a means for heating a domestic hot water supplysystem. rlhis type of heat exchange apparatus will perform mostefficiently if maintained in contact with the hot water and below thesteam boiler water line 3l at all times, as best indicated in Fig. 3.

To adapt this type of boiler for use with a gas burner, theinterchangeable sections 4 and 5 and the same type of dome section l2may be supported upon a modiiied base casing 40 provided with waterjacket spaces el on all four sides, but preferably not on the bottom,after the manner illustrated in Fig. 6. Any conventional type of gasburner having perpendicularly directed jets, such as the elementdesignated 42, may be utilized for this purpose, and an inlet arm 43 forsupporting the burner and conveying gas supply thereto may be suitablymounted for support within this casting, or it may be carried by. meansof leg brackets 44 which are associated with the base casting, asindicated in this gure. Both types of installations may be expected toperform more efciently when jacketed by an outer enclosure casing i5spaced from the principal casting sections and insulated therefrom byappropriate heat insulation material such as rock wool, fibre glass,etc.

While the present invention has been explained and described withreference to but few specio illustrations, it is to be understood,nevertheless, that numerous variations and modifications may be invokedwithout departing from the essential spirit and scope thereof.Accordingly, it is not intended to be limited by the specic details ofthe accompanying illustrations, nor by the particular wording in theforegoing detailed description, except as indicated in the hereuntoappended claims.

I claim:

1. A boiler section comprising a unitary casting affording higher andlower header sections, inclined ues connecting said header sections oftear-drop cross-section and having their small radius curvatureuppermost, said nues being lleted at their point of junction with saidhigher header in non-symmetrical radii so as to present minimum iiowresistance to contained uid in a direction outwardly oi the transversecenter oi said boiler section.

2. A boiler section comprising a casting of rectangular outline having aheader at each end, alined push nipple orices in the top andbottom`walls of each header, for tier assembly with other sections,perimetric flues connecting said headers and having perimetric definingflanges, and intermediate flues connecting said headers lieted at theirpoints of juncture with relatively larger radii in mean direction fromthe center flue outward and relatively smaller radii at each said pointsof juncture in opposite direction.

ROBERT C. CROSS.

